基于蜂窝网络的D2D通信传输模式选择方案

Transmission Mode Selection Scheme for D2D Communications Underlaying Cellular Networks

D2D技术作为5G通信的一项关键技术,其优势之一为利用D2D用户间的短距离通信来提高端到端的传输速率。而当D2D用户间距离较大时,由于用户发射功率有限,这一特性不再凸显。本文考虑利用中继技术增强D2D链路的性能。在传统D2D通信模型的基础上,本文进一步分析研究了放大转发(Amplify?and?forward,AF)和译码转发(Decode?and?forward,DF)两种中继辅助下的D2D通信模型,并提出了相应的模式间选择方案。特别地,该模式选择方案以闭式解的形式表述,且仅包含基本数学表达式。仿真结果表明,采用本文所提出的模式选择方案后,随着系统参数的变化,系统始终选择性能最优的通信模式进行端到端的通信,系统性能得到了显著提升。

Device?to?device(D2D)communication has attracted a lot of attention since it is considered as a key technology for 5G.The high rate can be obtained by the short distance between D2D users.However,this superiority will be lost when the distance between D2D users increases,since the transmit power of user is limited.Motivated by these,in order to improve the performance of D2D link,this paper investigates the D2D communication assisted with another D2D user working as a relay node.We consider three modes including traditional D2D communication,amplify?and?forward(AF)relay node assisted D2D communication and D2D communication aided by decode?and?forward(DF)relay node.In this paper,we analyze the achievable rate of each mode,and propose a mode selection scheme which is presented with closed?form expressions,which include only elementary functions.The mode selection scheme guarantees the D2D link always achieves the maximum rate of three modes.Numerical results show the significantly enhanced performance with the mode selection scheme.